Telescope Properties

Location

Telescope height

12 m

Altitude

5190 m

Ground screen height

13 m

Longitude

67° 47' 15"W

Total mass

52 t

Latitude

22° 57' 31"S

Moving Structure mass

40 t

Optics

f-numbera

2.5

Azimuth range

±220°

FOV

1 deg2

Max. az speed

2°/s

Primary reflector Dia

6m

Max. az acc.

10°/s2

No. primary panels

71

Elev. range

30.°5 - 60°

Secondary reflector Dia

2m

Max. elev speed

0.2°/s

No. secondary panels

11

aAt telescope Gregorian focus

ACT observes simultaneously in three frequency bands centered on 148 GHz, 218 GHz, and 277 GHz. These are often called AR1, AR2, and AR3 respectively. Celestial radiation in each band is imaged onto 32 X 32 arrays of transition-edge sensor (TES) bolometers. The arrays have the following properties: